@mixin linear-gradient($from, $to) {
    background-image: -moz-linear-gradient($from, $to);
    background-image: -webkit-gradient(linear, 0% 0%, 0% 100%, from($from), to($to));
    background-image: -webkit-linear-gradient($from, $to);
    background-image: -o-linear-gradient($from, $to);
    background-image: linear-gradient($from, $to);
}


// TODO: implement
@mixin radial-gradient($from, $to) {
}